Self cleaning filter



Aug. 11,'1931'. o.` v. GREENE r 1,318,391

sELE CLEANING FILTER A Filed May 4, 192s -2 sheets-snelst 1 EME NVENTOR.

scar V/-eefze BY I 1 @by 9M f @Eg ATTORNEY@ Aug. 1l 1931.

c. v. GREENEA v 1,818,391 SELF CLEANING JF'ILMR Filed Mayi4, 1929 2Sheets-sheet 2 l INVENTQIL Oo cr VfG/'6622 UML* ET Patentcdh'Aug. 11,1931 08m v. GREENE, OF CLEVELAND, OHIO SELF GLEANING FILTER applicatimeaicay 4; 192e. serial mi. seoaia.

The present invehtion relates to ainor dust' filters particularl adaptedfor use in connection with the lrtering of air for buildings and thelike, and more particularl provides "5 a filter mechanism which may,readil cleaned with'out removing it from the insta lation, the cleaninmeans being built in as aportion of the fi ter. To the accomplishment ofthe foregoin and related ends, said 10 invention then, consists of themeans hereinafter fully described and particularly inted out in theclaims; the annexed drawings and the following description setting forthin ldetail certain mechanism embodyu in g the invention, such disclosedmeans constituting, however, but one of various mechanical forms inwhich the principle of the i invention may be used.

Insaidannexed drawings: l zo Fig. 1 is a front elevational view vof thelter; Fig. ',2 is a side elevational view of the same; Fig. 3 is across-sectional view on the line 3-3 of Fi 1; Fi 4 is a sectional viewthrough one o the tering sheets; Fig. 5 zi is a front elevational viewof a unit heater showing a modified form; Fig. 6 is an end view o the.unit shown in Fig. 5 taken on the line 6-6 thereof ;`and Fig. 7 is asection of a detail.

In the present type of ilter there is provided a main frame 1 which hasa closed-in portion 2 at the top, in which is mounted a roller 3 havingits ends journaled in the side f frame members, and which is likewiseprovided at the bottom with a casing 4, in which a sec nd roller 5 ismounted, this roller being mou d in slots 6 so as to beverticallymovable and beingeof suilicient weight'to maintainthe filter lts 7 and 8under the desired tension. The' framework has a protecting sheet 9 ofheavy in front of the two belts 7 ands of ltering material. Each beltconsists of sheet 10 of relativel and a s eet 11 of -filter cloth, thesesheets being bound together to form a flexible unit lWthl-minimumstretch but with strength to resist wear and tear incidentto operation.-

The two belts are in, contactA where passing overthe rollers but arespaced apart through stantiall to which may be attache mesh wire screenmounted' coarse mesh flexible wire screen the main portion of the filtercasing by means of spacing rolls 15, the inner belt 8 passing over theinner sides of the rolls and being thus spaced from each other and fromthe A outer belts and being held under tension, the 55 rollers beingcarried by end bracketsi 51 which are pivotally mounted in the frame andwhich are held by a spring 52 connecting the bracket arm 53 and theframe. The space between belts is widest atthe vertical 30 ceiter of thefilter and the belts ap roach each other as they near the top and ottomwhere they pass over the .main rolls. In operation the belts are heldstationary until they have accumulated enough'dust and dirt g5 to makecleanin desirable.

YAs filters of t is t pe are commonly used onlyduring the daytime inbuilding installations, they may be'easily cleaned at night when theventilatin'g fans are shut down. 70 The cleaning' mechanism isbuilt intothe lower portion of the casing as an integral unit, this cleaninmechanism consisting, as shown of a pair o vacuum 4cleaning nozzles 16and 17 formed in the front of the casing 4 and sub- 75 covering the fullwi th of the filter. ese two nozzles are connected together by a pipe 18havinr a single outlet 19,

d the usual vacuum hose connection or vacuum cleaning consu nection ofany type. When it is desired to Vclean the filter, the vacuum hose isattached tothe connection and then the belts fare ro-A tated so as topass the outer surface ofthe belt over the vacuum cleaner nozzles 'thuse5 sucking the dirt back from the filter belts into the vacuum cleaner.The usual procedure is to move the belt around so that the sides of thetwo belts, which are normally at the rear ofthe filter, are reversed andare left `as the no i-st two or `front two belts of thefilter, althoughof course the belts can be completely cleaned, if this is desired.

To rotate the belts, the lower filter casing is provided with a platform2O on which c5 is'4 mounted a motor 21 and a speed reducing mechanism22, this mechanism driving a shaft 23 which extends along the rear ofthelower filter casing 4, this shafthaving a spocket 24 on itsouter end,preferably `chain 100 connected to a sprocket 25 which is carried 'on anextension of the lower roller 5. At

the other end the motor carries a pulley 26 which is referablybelt-connected to a beater roll 27 w 'ch is mounted in the front of Athecasing in substantial contact with the filter belts this roll beingprovided with lon'tul;

dinal projections, brushes or ribs 28 w beat against and jar the beltsas they are rotated. The beater roll is driven at high speed, whereasthe lower, belt roller 5 is driven at a very slow speed through thereduction gearing and the further speed reducover a curved plate 62along the top of the' lower casing while the-inner belt passes over anidler roller 63, the belts being, in contact t with each other and beingheld to prevent vibration above this horizontal line. The beater rolljars the belts 7 and 8between the idler rolls and the pressure linewhere thevbelt passes between the casing and the main roll 5, therebeing a sealing strip 64 mounted on the casing at this 'line to limitthe vibration of the belts to this area defined by the idler roll 63 andstrip 64 which is substan-V tially the size of the vacuum cleaningnozzle 36 being placed between the blower mechais attached a crank 48 sothat opening in the casing 4. Y The cleaning a'ction-is thus confined tothe nozzle area and vibration of the beltsabove such area, andconsequent dislodging of dust and dirt is prevented. Y

In Figs. l5 and 6 the same type 0f mechanism is applied to a unitheater, which consists of'a small casin 30 having a heating coil 31 nearthe top, outet openings 32,' a blower fan 33 and bottom inletopenings 34which are controlled by a damper 35i, the filter inlet nism 33 andthebottom openings`34, and here the filter unit, because of the limitedstatic capacities of the fans employed, consists prevferably of a singlebelt 40 similar in construction to the belts reviously described, this1n belt being mounte in ahframe carrying two. rollers 41 and 42, one ofwhich, 42, is springpressed outwardly to obtain the desired Vbe ttension. At one end of the casing a vacuum cleaner nozzle 44 is mountedto extend across and co-o erate with the belt, this nozzle heiligprovide with a suitable connection 45 whi communicates with the outsideof the casing, to which may be easily 'attached the vacuum hoseconnect-ion. To rotate the belt when it is' desired to clean the same,the' roll 41 at the vacuum cleaner end of the casing has one `end 47exposed through the casing, to which the roll may be lhaving sp slowlyrotated by hand, thus passing the belt across the vacuum cleaning nozzleat any desired speed, and the belt will be rotated by hand untilthoroughly cleaned. To accomplish this, the Ventilating mechanism, con-ysistng of the blower fan r the unit heater, is of course shut down whilethe vacuum cleaninf1r is being accomplished. In both forms abovedescribed, the filter elements and supporting frames are sealed toprevent any by-passing of dirtyair around the filter and direct the airflow throughthe several spaced elements in sequence.

The present type of filter is. particularly adapted forl use wherevacuum cleaning means are available and where it is desirable to make armanent installation as the cleaning of t e filter is automaticallaccomplished, thecleaning mechanism being built as 4an integral part ofthev filter mechanism itself. By the use of flexible belts, thedesirable beltps acing, that is, the spacingbetween individuav filterelements, is easily accomplished -and the cleaning is satisfactoi'g1 asthe outer belt onthe front side of the ter is that portion 'whichcollects the greatest amountlof lint and dust, and this is the belt, orportion of thebelt, which is directly in contact with the cleaningnozzle, and thus the dirt anddust rviseasily'and quickly removed. Y

Other modes of applyingthe rinciple of my invention may be ein loyeinstead of the one explained, change being made as regards the-mechanism hereinA disclosed, r0- vided the means stated by any of thefo owing claims or the equivalentof such stated` means'be employed.-

I therefore 'particularly point out and distinctl claim as my inventionl. a filter, the combination of a frame, having spaced rolls, an endlessfilter belt mounted in said frame over said rolls, a casing at one endof said frame, and having a vacuum .cleanin nozzle opening adjacent thebelt, means or holding the belt against said casing at the'top andbottom of said nozzle opening, other means in said casing for jarringsaid screen` at said opening, an ineans for moving said belt past saidopeng. l 2. In avfilter, the combination of aI frame,

said beater roll tovibrate said belt at sai loo' aced rolls, an endlessfilter belt j mounted in said frame over said rolls, a casopening, andYmeans for moving said belt past' p said opening.

. .3. In'lter construction, the combination of a frame, a rollermountedat each end of :,eiase;

said frame, two belts of filter material oxtending around said rollers,said belts bein continuous and in su rposed relation, an meansintermediate o -said rollers and adapted to engage the inner one of saidbelts to space the inner belt away from the other belt, and to space theportions of the inner belt betweenthe rollers from each other.

4. In filter construction, the combination of a frame, a rollermountedat each end of said frame, two beltsoflilter material'extendng aroundsaid rollers, said belts being` contin nous and in supe osed relation,and a pair .of rollers mounte in said frame at approxi-` n 1 5 matelyequal distances from said first rollers and adapted to have the inner ofsaid two t belts pass-over and in contact with the inner 1 surfaces ofthe rollers to space the inner belt -jfrom theouter belt, and to anicethe vlon'gi A 29 tugnal portions of the inner lt` from' ot er. 5y

5. In a filter, the combination of a frame, having spaced ro11s,twoendless filter-belts mounted 1n superposed relation in said fratriev 1over said rolls, a casing at one end: of'sfaid frame having a vacuumcleaning`v nozzle open-f! ing adjacent said belts, means for holding,said be ts a inst said casing at the top andA bottom of sai nozzleopenin ,other means casing for jarring sai screens at said opening, andmeans for moving said belts past said 0]?el1il1gn .l v I 'I' 6'. In afilter, the combination of a frame, 1 haw'ng spaced rolls, two endlessfilter belts f` mounted 1n superposed relation in said frame over saidrolls, ai casing at one end. of said frame having a vacuum cleaningnozzle o ning ad'acent .said belts, meanspfor hol in ,said be ts againstsaid casing at the top an 40 bottom of'said nozzle opening, a beaterroll mounted in said casing across said opening, means for rotatin saidbeater roll to vibrate said belts at sai openin and means for movingsaid belts ast sai o ening.

' 45 Signed by me this 3d day o May 192s. OSCAR v. GRENE.

